GB2136849A

GB2136849A - Method and equipment for controlling the floor of a gallery

Info

Publication number: GB2136849A
Application number: GB08308019A
Authority: GB
Inventors: Michael Schyma
Original assignee: HSB HYDRAULIK SCHLAUCHTECHNIK
Current assignee: HSB HYDRAULIK SCHLAUCHTECHNIK
Priority date: 1983-03-23
Filing date: 1983-03-23
Publication date: 1984-09-26
Also published as: GB2136849B; GB8308019D0

Abstract

The invention relates to a method of and equipment for controlling the floor of a gallery with gallery walling against upthrow of the floor layers. For this purpose floor piles 9 of prescribed lengths are inserted in the manner of a pile foundation into the rock 4 below the floor, adjacent the junction 5 between the floor and the wall of the gallery. The gallery wall lining 3 is erected on the floor piles. The pressures building up in the wall areas are thereby transmitted to distant portions of the rock below the floor. <IMAGE>

Description

SPECIFICATION Method and equipment for controlling the floor of a gallery This invention relates to a method for control ling the floor of a gallery in underground workings against upthrow of the floor layers.

With in the scope of the invention "galleries" are understood to include headings, cross headings, stalls, seam galleries, ventilation galleries, etc. The invention also embraces the construction of tunnels.

The upthrow or heaving of the floor layers of a gallery is chiefly explained by the differ ing rock pressures that arise from the driving of cavities and the subsequent extraction of minerals in underground operations. These pressures force upwards the floor layers into the cavity formed by the gallery. In order to maintain a permanent adequate gallery crosssection, the floor layers that are thrown up must according be removed. Whilst soft floor layers can be removed by loading machines, firm floor layers generally require blasting operations to break up the floor rock that is thrown up, and blasting work of this kind is uncertain. With rigid floors, attempts have been made to control the floor level by the application of a number of floor anchors in radial array obliquely across the floor. This is expensive, and anchors of this kind are unsuited to yielding floors.In such cases the rock faces and floor of the galiey are frequently slotted, to relieve pressure on the rock that enshrouds the gallery. Production of stressrelieving slots of this kind is similarly expensive.

It is the object of the invention to provide a method and equipment by which a gallery floor can be controlled in relatively simple and certain manner, i.e. that enables the upthrow of the floor layers to be prevented independently of the rigidity of such layers.

According to the present invention, a method for controlling the floor of a gallery in underground workings against upthrow of the floor layers, in which mounting units for the posts of gallery wall linings are located adjacent the junction between the gallery wall and the floor, and are anchored into the floor by anchoring units, in which the mounting units are inserted in the manner of a pile foundation as floor piles extending into layers of rock below the floor and which are able to carry the inwardly directed pressures that build up in the gallery walls, on which piles the gallery wall lining is erected. The invention arises from the recognition that fracture and upthrow of the floor of the gallery particularly takes place because the pressures that build up in the region of the rock faces of the gallery are transmitted to the uppermost layers of the floor via the gallery walls.The gallery walls are forced into the floor and disrupts the uppermost floor layers. With the invention this is avoided, because the gallery walls and the walling posts or walling arches are erected on a pile foundation. The floor piles receive the pressures exerted via the gallery walling and convey them to deeply-lying layers of the floor or into the more distant rock. Thereby the upper layers of the floor remain basically undisturbed, or in any case the pressure peaks that would otherwise occur in them are so displaced that a considerable reduction of stress concentration is achieved.

Further important features of the invention are described as follows. Thus the invention, according to a proposal of independent importance teaches that in order to introduce the floor piles into the gallery floor essentially vertical drilled holes are produced at the spacings of the lining posts, then pile bars are inserted into the drilled holes and finally the drilled holes are filled up with cement mortar or concrete, or are filled with an adhesive compound before insertion of the pile bars.

Appropriate materials as adhesive compounds are for example plastics mixtures based on polyester resins, which are introduced into the drilled holes in the form of cartridges before the placing of the pile bars.

Preferably pile bars with pile heads formed as footplates for the gallery wall lining posts are used so that perfect setting up or erection of the gallery wall lining is ensured. According to another proposal of the invention it is provided that pile bars formed as anchors with anchor plates formed as footplates fotr the gallery wall lining are used. Accordingly the load-bearing capacity of the rock in the region of the floor layers is additionally increased.

An equipment to perform the above defined method, which is notable for a particularly simple and reliably-operating construction, is also within the scope of the invention. This equipment is characterized by a pile bar with a pile head formed as a footplate, e.g. a Ushaped footplate. Also the pile bar can have a pile shoe, i.e. a widened pile foot, to reduce the peak pressure by transmitting pressure forces to the more distant portions of the rock.

Another form of construction of the invention is characterized by a pile bar formed as an anchor with an anchor plate formed as a footplate, e.g. a U-shaped footplate. Thus the anchor plate, can simultaneously fulfil the function of the foot plate for perfect setting of the gallery wall lining posts.

The advantages achieved by the invention are that a method to control the floor of a gallery is disclosed, that prevents the upthrow of the floor layers in a simple and reliablyoperating manner, or at least prevents it to suuch an extent that troublesome reduction of the cross-sectional area of the gallery is prevented and the loading operations and possibly blasting operations otherwise necessary to carry away the upsurged floor of the galley are avoided. Consequently, the method of the invention contributes to a considerable degree to improvement of the condition of the gallery, so that the expenditure on labour otherwise necessary for the maintenance of mining galleries can be reduced.

One example of the invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a schematic representation in vertical cross-section of a mining gallery with upthrown floor layers; and Figure 2 shows a mining gallery with floor piles introduced by the method according to the invention.

tn the drawings like reference numerals have been used for the corresponding items.

Thus in Fig. 1 a conventional mining gallery is shown having a floor 1, an extracted gallery 2 and a lining 3 adjacent the gallery wall. The inevitable build up of pressure in the galley wall is transmitted to the floor predominately at the junction 5 between the floor and the wall, causing the surface layers 4 of the floor to lift and partially obstruct the gallery.

With the invention as is shown in Fig. 2 floor piles 6 of prescribed lengths are inserted in the manner of a pile foundation adjacent the junction 5 between the floor of the gallery 1 and the wall. The length of the piles 6 is so selected that they penetrate into rigid rock 7, which is suitable to receive the rock pressures arising in the walls. As these rock pressures are transmitted via the gallery wall lining 3 or its walling posts or walling arches, the gallery wall lining 3 is erected on the floor piles 6 so that the rock pressures that would otherwise cause upthrow of the floor layers are now conveyed into rock 7 lying at a considerable distance below the floor. To introduce the floor piles 6 into the gallery floor essentially vertically-drilled holes 8 are produced at the spacings of the lining posts. Then pile bars 9 are inserted into the drilled holes 8 and finally drilled holes 8 are filled up with cement mortar 10 or concrete. The possibility however also exists of filling the drilled holes 8 with adhesive compound or adhesive cartridges before the insertion of the pile bars 9.

In the example shown, pile bars 9 with pile heads formed as footplates 11 for the gallery walling 3, are used.

Claims

1. A method for controlling the floor of a gallery in underground workings against upthrow of the floor layers, in which mounting units for the posts of gallery wall linings are located adjacent the junction between the gallery wall and the floor, and are anchored into the floor by anchoring units, wherein the mounting units are inserted in the manner of a pile foundation as floor piles extending into layers of rock below the floor and which are able to carry the inwardly directed pressures that build up in the gallery walls, on which piles the gallery wall lining is erected.

2. A method as in Claim 1, wherein to insert the floor piles into the gallery floor, essentially vertical drilled holes are produced at the spacings required for the posts, pile bars then being inserted into the drilled holes and finally the drilled holes filled with cement mortar or concrete or filled with an adhesive compound before insertion of the pile bars.

3. A method as in Claim 1 or Claim 2, wherein the pile bars are provided with pile heads formed as footplates for the gallery lining posts.

4. A method as in Claim 1 or Claim 2, wherein pile bars formed as anchoring rods, with anchor plates formed as footplates for the gallery lining posts are used.

5. Equipment for performing the method according to any of Claims 1 to 3, comprising a mounting unit for the reception of a post of the gallery wall lining, the mounting unit consisting of a pile bar with a pile head formed as a footplate for the post anchored in the rock below the floor adjacent the junction between the floor and the wall of the gallery.

6. Equipment as in Claim 5, wherein the footplate is U-shaped.

7. Equipment as in Claim 5 or Claim 6, wherein the pile rod has a pile shoe facing towards the lowest part of the drilled hole.

8. Equipment for performing the method according to any one of Claims 1 to 4, comprising a mounting unit for the reception of a post of the gallery walling, anchored in the rock below the floor adjacent the junction between the floor and wall of the gallery, the mounting element consisting of a rock anchor bolt and an associated anchor plate that is formed as a U-shaped post footplate.

9. A method for controlling the floor of a gallery substantially as hereinbefore described with reference to Fig. 2 of the accompanying drawings.

10. Equipment for performing the method of Claim 1, and substantially as hereinbefore described with reference to Fig. 2 of the accompanying drawings.